Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).
Find the minimum element.
You may assume no duplicate exists in the array.
Example 1:
Input: [3,4,5,1,2] Output: 1
Example 2:
Input: [4,5,6,7,0,1,2] Output: 0
link:{sourcedir}/_0153_FindMinimumInRotatedSortedArray.java[role=include]
最省事的方式当然是遍历，但是，中等难度的题目不可能一个遍历就解决了。
针对有序数组，首先想到的就是二分查找。但是，这里的二分查找有需要做些特别处理。尤其注意的是，选出 mid 后，先去判断它或者它的邻居是否满足条件，满足就直接返回。然后再去调整范围。